Soft Tread Casters For Hard Surface Floors by North American Caster Limited Twin wheel design and soft polyurethane treads for easier and quieter mobility than standard plastic casters For use on hard surface floors, such as hardwood, laminate, ceramic, marble, stone and cement. Not suitable for cork floors Can be used in office chairs, store fixtures, display units, office equipment, utility carts, and much more Maximum weight of 375lbs (170kgs) Each package contains 5 casters with full 360 degree rotation